1 /* 2 * Virtio Support 3 * 4 * Copyright IBM, Corp. 2007 5 * 6 * Authors: 7 * Anthony Liguori <aliguori@us.ibm.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2. See 10 * the COPYING file in the top-level directory. 11 * 12 */ 13 14 #ifndef QEMU_VIRTIO_H 15 #define QEMU_VIRTIO_H 16 17 #include "exec/memory.h" 18 #include "hw/qdev-core.h" 19 #include "net/net.h" 20 #include "migration/vmstate.h" 21 #include "qemu/event_notifier.h" 22 #include "standard-headers/linux/virtio_config.h" 23 #include "standard-headers/linux/virtio_ring.h" 24 #include "qom/object.h" 25 26 /* 27 * A guest should never accept this. It implies negotiation is broken 28 * between the driver frontend and the device. This bit is re-used for 29 * vhost-user to advertise VHOST_USER_F_PROTOCOL_FEATURES between QEMU 30 * and a vhost-user backend. 31 */ 32 #define VIRTIO_F_BAD_FEATURE 30 33 34 #define VIRTIO_LEGACY_FEATURES ((0x1ULL << VIRTIO_F_BAD_FEATURE) | \ 35 (0x1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | \ 36 (0x1ULL << VIRTIO_F_ANY_LAYOUT)) 37 38 struct VirtQueue; 39 40 static inline hwaddr vring_align(hwaddr addr, 41 unsigned long align) 42 { 43 return QEMU_ALIGN_UP(addr, align); 44 } 45 46 typedef struct VirtIOFeature { 47 uint64_t flags; 48 size_t end; 49 } VirtIOFeature; 50 51 typedef struct VirtIOConfigSizeParams { 52 size_t min_size; 53 size_t max_size; 54 const VirtIOFeature *feature_sizes; 55 } VirtIOConfigSizeParams; 56 57 size_t virtio_get_config_size(const VirtIOConfigSizeParams *params, 58 uint64_t host_features); 59 60 typedef struct VirtQueue VirtQueue; 61 62 #define VIRTQUEUE_MAX_SIZE 1024 63 64 typedef struct VirtQueueElement 65 { 66 unsigned int index; 67 unsigned int len; 68 unsigned int ndescs; 69 unsigned int out_num; 70 unsigned int in_num; 71 hwaddr *in_addr; 72 hwaddr *out_addr; 73 struct iovec *in_sg; 74 struct iovec *out_sg; 75 } VirtQueueElement; 76 77 #define VIRTIO_QUEUE_MAX 1024 78 79 #define VIRTIO_NO_VECTOR 0xffff 80 81 /* special index value used internally for config irqs */ 82 #define VIRTIO_CONFIG_IRQ_IDX -1 83 84 #define TYPE_VIRTIO_DEVICE "virtio-device" 85 OBJECT_DECLARE_TYPE(VirtIODevice, VirtioDeviceClass, VIRTIO_DEVICE) 86 87 typedef struct { 88 int virtio_bit; 89 const char *feature_desc; 90 } qmp_virtio_feature_map_t; 91 92 enum virtio_device_endian { 93 VIRTIO_DEVICE_ENDIAN_UNKNOWN, 94 VIRTIO_DEVICE_ENDIAN_LITTLE, 95 VIRTIO_DEVICE_ENDIAN_BIG, 96 }; 97 98 /** 99 * struct VirtIODevice - common VirtIO structure 100 * @name: name of the device 101 * @status: VirtIO Device Status field 102 * 103 */ 104 struct VirtIODevice 105 { 106 DeviceState parent_obj; 107 const char *name; 108 uint8_t status; 109 uint8_t isr; 110 uint16_t queue_sel; 111 /** 112 * These fields represent a set of VirtIO features at various 113 * levels of the stack. @host_features indicates the complete 114 * feature set the VirtIO device can offer to the driver. 115 * @guest_features indicates which features the VirtIO driver has 116 * selected by writing to the feature register. Finally 117 * @backend_features represents everything supported by the 118 * backend (e.g. vhost) and could potentially be a subset of the 119 * total feature set offered by QEMU. 120 */ 121 uint64_t host_features; 122 uint64_t guest_features; 123 uint64_t backend_features; 124 125 size_t config_len; 126 void *config; 127 uint16_t config_vector; 128 uint32_t generation; 129 int nvectors; 130 VirtQueue *vq; 131 MemoryListener listener; 132 uint16_t device_id; 133 /* @vm_running: current VM running state via virtio_vmstate_change() */ 134 bool vm_running; 135 bool broken; /* device in invalid state, needs reset */ 136 bool use_disabled_flag; /* allow use of 'disable' flag when needed */ 137 bool disabled; /* device in temporarily disabled state */ 138 /** 139 * @use_started: true if the @started flag should be used to check the 140 * current state of the VirtIO device. Otherwise status bits 141 * should be checked for a current status of the device. 142 * @use_started is only set via QMP and defaults to true for all 143 * modern machines (since 4.1). 144 */ 145 bool use_started; 146 bool started; 147 bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */ 148 bool disable_legacy_check; 149 bool vhost_started; 150 VMChangeStateEntry *vmstate; 151 char *bus_name; 152 uint8_t device_endian; 153 bool use_guest_notifier_mask; 154 AddressSpace *dma_as; 155 QLIST_HEAD(, VirtQueue) *vector_queues; 156 QTAILQ_ENTRY(VirtIODevice) next; 157 EventNotifier config_notifier; 158 bool device_iotlb_enabled; 159 }; 160 161 struct VirtioDeviceClass { 162 /*< private >*/ 163 DeviceClass parent; 164 /*< public >*/ 165 166 /* This is what a VirtioDevice must implement */ 167 DeviceRealize realize; 168 DeviceUnrealize unrealize; 169 uint64_t (*get_features)(VirtIODevice *vdev, 170 uint64_t requested_features, 171 Error **errp); 172 uint64_t (*bad_features)(VirtIODevice *vdev); 173 void (*set_features)(VirtIODevice *vdev, uint64_t val); 174 int (*validate_features)(VirtIODevice *vdev); 175 void (*get_config)(VirtIODevice *vdev, uint8_t *config); 176 void (*set_config)(VirtIODevice *vdev, const uint8_t *config); 177 void (*reset)(VirtIODevice *vdev); 178 void (*set_status)(VirtIODevice *vdev, uint8_t val); 179 /* Device must validate queue_index. */ 180 void (*queue_reset)(VirtIODevice *vdev, uint32_t queue_index); 181 /* Device must validate queue_index. */ 182 void (*queue_enable)(VirtIODevice *vdev, uint32_t queue_index); 183 /* For transitional devices, this is a bitmap of features 184 * that are only exposed on the legacy interface but not 185 * the modern one. 186 */ 187 uint64_t legacy_features; 188 /* Test and clear event pending status. 189 * Should be called after unmask to avoid losing events. 190 * If backend does not support masking, 191 * must check in frontend instead. 192 */ 193 bool (*guest_notifier_pending)(VirtIODevice *vdev, int n); 194 /* Mask/unmask events from this vq. Any events reported 195 * while masked will become pending. 196 * If backend does not support masking, 197 * must mask in frontend instead. 198 */ 199 void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask); 200 int (*start_ioeventfd)(VirtIODevice *vdev); 201 void (*stop_ioeventfd)(VirtIODevice *vdev); 202 /* Saving and loading of a device; trying to deprecate save/load 203 * use vmsd for new devices. 204 */ 205 void (*save)(VirtIODevice *vdev, QEMUFile *f); 206 int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id); 207 /* Post load hook in vmsd is called early while device is processed, and 208 * when VirtIODevice isn't fully initialized. Devices should use this instead, 209 * unless they specifically want to verify the migration stream as it's 210 * processed, e.g. for bounds checking. 211 */ 212 int (*post_load)(VirtIODevice *vdev); 213 const VMStateDescription *vmsd; 214 bool (*primary_unplug_pending)(void *opaque); 215 struct vhost_dev *(*get_vhost)(VirtIODevice *vdev); 216 void (*toggle_device_iotlb)(VirtIODevice *vdev); 217 }; 218 219 void virtio_instance_init_common(Object *proxy_obj, void *data, 220 size_t vdev_size, const char *vdev_name); 221 222 void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size); 223 224 void virtio_cleanup(VirtIODevice *vdev); 225 226 void virtio_error(VirtIODevice *vdev, const char *fmt, ...) G_GNUC_PRINTF(2, 3); 227 228 /* Set the child bus name. */ 229 void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name); 230 231 typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *); 232 233 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, 234 VirtIOHandleOutput handle_output); 235 236 void virtio_del_queue(VirtIODevice *vdev, int n); 237 238 void virtio_delete_queue(VirtQueue *vq); 239 240 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem, 241 unsigned int len); 242 void virtqueue_flush(VirtQueue *vq, unsigned int count); 243 void virtqueue_detach_element(VirtQueue *vq, const VirtQueueElement *elem, 244 unsigned int len); 245 void virtqueue_unpop(VirtQueue *vq, const VirtQueueElement *elem, 246 unsigned int len); 247 bool virtqueue_rewind(VirtQueue *vq, unsigned int num); 248 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem, 249 unsigned int len, unsigned int idx); 250 251 void virtqueue_map(VirtIODevice *vdev, VirtQueueElement *elem); 252 void *virtqueue_pop(VirtQueue *vq, size_t sz); 253 unsigned int virtqueue_drop_all(VirtQueue *vq); 254 void *qemu_get_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, size_t sz); 255 void qemu_put_virtqueue_element(VirtIODevice *vdev, QEMUFile *f, 256 VirtQueueElement *elem); 257 int virtqueue_avail_bytes(VirtQueue *vq, unsigned int in_bytes, 258 unsigned int out_bytes); 259 void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, 260 unsigned int *out_bytes, 261 unsigned max_in_bytes, unsigned max_out_bytes); 262 263 void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq); 264 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq); 265 266 int virtio_save(VirtIODevice *vdev, QEMUFile *f); 267 268 extern const VMStateInfo virtio_vmstate_info; 269 270 #define VMSTATE_VIRTIO_DEVICE \ 271 { \ 272 .name = "virtio", \ 273 .info = &virtio_vmstate_info, \ 274 .flags = VMS_SINGLE, \ 275 } 276 277 int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id); 278 279 /** 280 * virtio_notify_config() - signal a change to device config 281 * @vdev: the virtio device 282 * 283 * Assuming the virtio device is up (VIRTIO_CONFIG_S_DRIVER_OK) this 284 * will trigger a guest interrupt and update the config version. 285 */ 286 void virtio_notify_config(VirtIODevice *vdev); 287 288 bool virtio_queue_get_notification(VirtQueue *vq); 289 void virtio_queue_set_notification(VirtQueue *vq, int enable); 290 291 int virtio_queue_ready(VirtQueue *vq); 292 293 int virtio_queue_empty(VirtQueue *vq); 294 295 /* Host binding interface. */ 296 297 uint32_t virtio_config_readb(VirtIODevice *vdev, uint32_t addr); 298 uint32_t virtio_config_readw(VirtIODevice *vdev, uint32_t addr); 299 uint32_t virtio_config_readl(VirtIODevice *vdev, uint32_t addr); 300 void virtio_config_writeb(VirtIODevice *vdev, uint32_t addr, uint32_t data); 301 void virtio_config_writew(VirtIODevice *vdev, uint32_t addr, uint32_t data); 302 void virtio_config_writel(VirtIODevice *vdev, uint32_t addr, uint32_t data); 303 uint32_t virtio_config_modern_readb(VirtIODevice *vdev, uint32_t addr); 304 uint32_t virtio_config_modern_readw(VirtIODevice *vdev, uint32_t addr); 305 uint32_t virtio_config_modern_readl(VirtIODevice *vdev, uint32_t addr); 306 void virtio_config_modern_writeb(VirtIODevice *vdev, 307 uint32_t addr, uint32_t data); 308 void virtio_config_modern_writew(VirtIODevice *vdev, 309 uint32_t addr, uint32_t data); 310 void virtio_config_modern_writel(VirtIODevice *vdev, 311 uint32_t addr, uint32_t data); 312 void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr); 313 hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n); 314 void virtio_queue_set_num(VirtIODevice *vdev, int n, int num); 315 int virtio_queue_get_num(VirtIODevice *vdev, int n); 316 int virtio_queue_get_max_num(VirtIODevice *vdev, int n); 317 int virtio_get_num_queues(VirtIODevice *vdev); 318 void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc, 319 hwaddr avail, hwaddr used); 320 void virtio_queue_update_rings(VirtIODevice *vdev, int n); 321 void virtio_init_region_cache(VirtIODevice *vdev, int n); 322 void virtio_queue_set_align(VirtIODevice *vdev, int n, int align); 323 void virtio_queue_notify(VirtIODevice *vdev, int n); 324 uint16_t virtio_queue_vector(VirtIODevice *vdev, int n); 325 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector); 326 int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev, int n, 327 MemoryRegion *mr, bool assign); 328 int virtio_set_status(VirtIODevice *vdev, uint8_t val); 329 void virtio_reset(void *opaque); 330 void virtio_queue_reset(VirtIODevice *vdev, uint32_t queue_index); 331 void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index); 332 void virtio_update_irq(VirtIODevice *vdev); 333 int virtio_set_features(VirtIODevice *vdev, uint64_t val); 334 335 /* Base devices. */ 336 typedef struct VirtIOBlkConf VirtIOBlkConf; 337 struct virtio_net_conf; 338 typedef struct virtio_serial_conf virtio_serial_conf; 339 typedef struct virtio_input_conf virtio_input_conf; 340 typedef struct VirtIOSCSIConf VirtIOSCSIConf; 341 typedef struct VirtIORNGConf VirtIORNGConf; 342 343 #define DEFINE_VIRTIO_COMMON_FEATURES(_state, _field) \ 344 DEFINE_PROP_BIT64("indirect_desc", _state, _field, \ 345 VIRTIO_RING_F_INDIRECT_DESC, true), \ 346 DEFINE_PROP_BIT64("event_idx", _state, _field, \ 347 VIRTIO_RING_F_EVENT_IDX, true), \ 348 DEFINE_PROP_BIT64("notify_on_empty", _state, _field, \ 349 VIRTIO_F_NOTIFY_ON_EMPTY, true), \ 350 DEFINE_PROP_BIT64("any_layout", _state, _field, \ 351 VIRTIO_F_ANY_LAYOUT, true), \ 352 DEFINE_PROP_BIT64("iommu_platform", _state, _field, \ 353 VIRTIO_F_IOMMU_PLATFORM, false), \ 354 DEFINE_PROP_BIT64("packed", _state, _field, \ 355 VIRTIO_F_RING_PACKED, false), \ 356 DEFINE_PROP_BIT64("queue_reset", _state, _field, \ 357 VIRTIO_F_RING_RESET, true) 358 359 hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n); 360 bool virtio_queue_enabled_legacy(VirtIODevice *vdev, int n); 361 bool virtio_queue_enabled(VirtIODevice *vdev, int n); 362 hwaddr virtio_queue_get_avail_addr(VirtIODevice *vdev, int n); 363 hwaddr virtio_queue_get_used_addr(VirtIODevice *vdev, int n); 364 hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n); 365 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n); 366 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n); 367 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n); 368 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, 369 unsigned int idx); 370 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n); 371 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n); 372 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n); 373 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n); 374 uint16_t virtio_get_queue_index(VirtQueue *vq); 375 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq); 376 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign, 377 bool with_irqfd); 378 int virtio_device_start_ioeventfd(VirtIODevice *vdev); 379 int virtio_device_grab_ioeventfd(VirtIODevice *vdev); 380 void virtio_device_release_ioeventfd(VirtIODevice *vdev); 381 bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev); 382 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq); 383 void virtio_queue_set_host_notifier_enabled(VirtQueue *vq, bool enabled); 384 void virtio_queue_host_notifier_read(EventNotifier *n); 385 void virtio_queue_aio_attach_host_notifier(VirtQueue *vq, AioContext *ctx); 386 void virtio_queue_aio_attach_host_notifier_no_poll(VirtQueue *vq, AioContext *ctx); 387 void virtio_queue_aio_detach_host_notifier(VirtQueue *vq, AioContext *ctx); 388 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector); 389 VirtQueue *virtio_vector_next_queue(VirtQueue *vq); 390 EventNotifier *virtio_config_get_guest_notifier(VirtIODevice *vdev); 391 void virtio_config_set_guest_notifier_fd_handler(VirtIODevice *vdev, 392 bool assign, bool with_irqfd); 393 394 static inline void virtio_add_feature(uint64_t *features, unsigned int fbit) 395 { 396 assert(fbit < 64); 397 *features |= (1ULL << fbit); 398 } 399 400 static inline void virtio_clear_feature(uint64_t *features, unsigned int fbit) 401 { 402 assert(fbit < 64); 403 *features &= ~(1ULL << fbit); 404 } 405 406 static inline bool virtio_has_feature(uint64_t features, unsigned int fbit) 407 { 408 assert(fbit < 64); 409 return !!(features & (1ULL << fbit)); 410 } 411 412 static inline bool virtio_vdev_has_feature(const VirtIODevice *vdev, 413 unsigned int fbit) 414 { 415 return virtio_has_feature(vdev->guest_features, fbit); 416 } 417 418 static inline bool virtio_host_has_feature(VirtIODevice *vdev, 419 unsigned int fbit) 420 { 421 return virtio_has_feature(vdev->host_features, fbit); 422 } 423 424 static inline bool virtio_is_big_endian(VirtIODevice *vdev) 425 { 426 if (!virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) { 427 assert(vdev->device_endian != VIRTIO_DEVICE_ENDIAN_UNKNOWN); 428 return vdev->device_endian == VIRTIO_DEVICE_ENDIAN_BIG; 429 } 430 /* Devices conforming to VIRTIO 1.0 or later are always LE. */ 431 return false; 432 } 433 434 /** 435 * virtio_device_started() - check if device started 436 * @vdev - the VirtIO device 437 * @status - the devices status bits 438 * 439 * Check if the device is started. For most modern machines this is 440 * tracked via the @vdev->started field (to support migration), 441 * otherwise we check for the final negotiated status bit that 442 * indicates everything is ready. 443 */ 444 static inline bool virtio_device_started(VirtIODevice *vdev, uint8_t status) 445 { 446 if (vdev->use_started) { 447 return vdev->started; 448 } 449 450 return status & VIRTIO_CONFIG_S_DRIVER_OK; 451 } 452 453 /** 454 * virtio_device_should_start() - check if device startable 455 * @vdev - the VirtIO device 456 * @status - the devices status bits 457 * 458 * This is similar to virtio_device_started() but also encapsulates a 459 * check on the VM status which would prevent a device starting 460 * anyway. 461 */ 462 static inline bool virtio_device_should_start(VirtIODevice *vdev, uint8_t status) 463 { 464 if (!vdev->vm_running) { 465 return false; 466 } 467 468 return virtio_device_started(vdev, status); 469 } 470 471 static inline void virtio_set_started(VirtIODevice *vdev, bool started) 472 { 473 if (started) { 474 vdev->start_on_kick = false; 475 } 476 477 if (vdev->use_started) { 478 vdev->started = started; 479 } 480 } 481 482 static inline void virtio_set_disabled(VirtIODevice *vdev, bool disable) 483 { 484 if (vdev->use_disabled_flag) { 485 vdev->disabled = disable; 486 } 487 } 488 489 static inline bool virtio_device_disabled(VirtIODevice *vdev) 490 { 491 return unlikely(vdev->disabled || vdev->broken); 492 } 493 494 bool virtio_legacy_allowed(VirtIODevice *vdev); 495 bool virtio_legacy_check_disabled(VirtIODevice *vdev); 496 497 #endif 498